21621599

Appears in sequences

• Numbers k where records occur for sigma(k+1)/sigma(k), where sigma(k) is the sum of divisors of k (A000203).at n=25A335067
• Numbers k such that, via a residue based measure M(k) (see Comments), k is deficient, k+1 is abundant, and abs(M(k)) + abs(M(k+1)) reaches a new maximum.at n=32A362083